Reduce needless groonga-normalizer-mysql checks
Reduce needless groonga-normalizer-mysql checks

naoa/mroonga,naoa/mroonga,yoku0825/mroonga,naoa/mroonga,naoa/mroonga,mroonga/mroonga,naoa/mroonga,naoa/mroonga,yoku0825/mroonga,mroonga/mroonga,yoku0825/mroonga,mroonga/mroonga,yoku0825/mroonga,yoku0825/mroonga,mroonga/mroonga,yoku0825/mroonga